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/Dinosaur and Prehistoric Animal News Stories

Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

19 01, 2020

Little Dancing Dragon Sheds Light on How Dinosaurs Grew Up

By | January 19th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

The New Microraptorine Wulong bohaiensis

A new feathered dinosaur from Liaoning Province (north-eastern China), has been named and described.  The little dinosaur, not much bigger than a crow, but with a long tail, has been named Wulong bohaiensis.  The fossilised feathers associated with the beautifully preserved skeleton, include two long tail feathers, the sort of extravagant plumage associated with mature birds which use such adornments to attract a mate.  However, when an analysis of the limb bones was undertaken to determine the age of the specimen (histological analysis), the research team discovered that the specimen represented a juvenile.

Either those long, showy feathers served some other function, or dinosaurs that were closely related to birds grew up differently when compared to their living relatives.

The Newly Described Wulong bohaiensis.

Wulong bohaiensis fossil specimen.

The beautifully preserved and almost complete W. bohaiensis fossil specimen.

Picture Credit: Ashley W. Poust (University of California)

Dancing Dragon

The fossil specimen was found more than ten years ago by a local farmer.  It had resided in the vertebrate collection of the Dalian Natural History Museum (Liaoning Province), being eventually described and studied by scientists at the museum in conjunction with student Ashley Poust under the supervision of  Dr David Varricchio (Montana State University), her former advisor, prior to Ashley moving to the University of California.

The genus name is Chinese for “dancing dragon”, a reference to the posture of the preserved specimen.  A phylogenetic analysis places W. bohaiensis within Microraptorinae, this little dinosaur was therefore closely related to Microraptor.  Whether, like Microraptor, Wulong bohaiensis was capable of powered flight can be speculated upon.

Ashley Poust explained the significance of this research stating:

“The specimen has feathers on its limbs and tail that we associate with adult birds, but it had other features that made us think it was a juvenile.”

In order to determine the age of the dinosaur when it died, staff at the Dalian Natural History Museum gave permission for the tibia, fibula and humerus bones to be examined histologically.  Essentially, cross-sectional slices of these bones were removed from the skeleton, prepared and then examined under a microscope so that the seasonal/annual growth of the animal could be identified.  Such a technique is invasive and will cause damage to the fossil specimen, fortunately, the curators at the Dalian Natural History Museum took the decision that in order to benefit science the invasive procedures had to be undertaken.

Ashley commented:

“Thankfully, our co-authors at the Dalian Natural History Museum were really forward thinking and allowed us to apply these techniques, not only to Wulong, but also to another dinosaur, a close relative that looked more adult called Sinornithosaurus.”

A Life Reconstruction of Wulong bohaiensis

Life reconstruction of Wulong bohaiensis.

A life reconstruction of Wulong bohaiensis.  The sharp, small teeth in the jaw of Wulong suggest that this dinosaur was a piscivore, or perhaps feeding on insects.

Picture Credit: Ashley Poust (University of California)

Sinornithosaurus Provides a Surprise

The histology of a specimen of another feathered dinosaur associated with the Early Cretaceous Jehol biota was also examined.  The research team wanted to compare their immature, juvenile Wulong to what they thought was a specimen of an adult Sinornithosaurus.  However, analysis of the bone structure of the Sinornithosaurus provided a surprise.  The histology revealed that both specimens were young and still growing at death, indicating an age for Wulong of about one-year-old.

Commenting on the results of the histological analysis on the Sinornithosaurus specimen, Ashley explained:

“Here was an animal that was large and had adult looking bones.  We thought it was going to be mature, but histology proved that idea wrong.  It was older than Wulong, but seems to have been still growing.  Researchers need to be really careful about determining whether a specimen is adult or not.  Until we learn a lot more, histology is really the most dependable way.”

An Illustration of Sinornithosaurus

Sinornithosaurus

The fearsome dromaeosaurid Sinornithosaurus, in reality this dinosaur was about 1-1.2 metres in length, although it might have preyed upon the smaller Wulong bohaiensis.

Picture Credit: Zhao Chuang

This new study suggests that either young dinosaurs developed elaborate tail feathers for some other purpose, or that they were growing feathers in a different way from their close living relatives the Aves (birds).

The Paraves Clade

The Paraves is a clade of theropod dinosaurs.  It is defined as containing all the dinosaurs which are more closely related to birds than to oviraptorosaurs.  As such it includes troodontids, dromaeosaurids and avialians, which encompasses extant birds.  Much of what we know about the diversity of this group in the Early Cretaceous comes from fossil specimens found in Liaoning, China.  However, many taxa are represented by specimens of unclear ontogenetic age.  With a better understanding of how dinosaurs may have changed in their appearance as they grew up, scientists can be more confident about their phylogeny, their evolutionary relationships and which character traits can be used to infer biology and the dinosaur’s position within the complex Jehol ecosystem.

This scientific paper identified several different types of feather associated with Wulong bohaiensis – pennaceous primary feathers, filamentous feathers and long tail feathers.  The team established that such plumage preceded skeletal maturity and full adult size in some dromaeosaurids.  Histological analysis of the Wulong holotype and a Sinornithosaurus specimen revealed that they developed mature feather coverings associated with adult animals after their first year, but before they had become fully grown.  This has implications for Paraves research as assumptions made about the adult age of a fossil specimen may not be accurate in the absence of histological analysis.

The scientific paper: “A new microraptorine theropod from the Jehol Biota and growth in early dromaeosaurids” by Ashley W. Poust, Chunling Gao, David J. Varricchio, Jianlin Wu, and Fengjiao Zhang published in The Anatomical Record.

17 01, 2020

Extra-terrestrial Impact Wiped Out the Dinosaurs

By | January 17th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page|2 Comments

Mass Extinction Event Caused by Impact Event

One of the greatest controversies surrounding the Dinosauria is what actually caused the demise of the non-avian dinosaurs?  Around the end-Cretaceous mass extinction event, there was an enormous extra-terrestrial impact in the Gulf of Mexico.  A worldwide layer of clay, saturated in the rare Earth element iridium, marking the K-Pg geological boundary was first publicised by American father and son Luis and Walter Alvarez.  They postulated that an Earth impact event had resulted in this deposition and it was speculated that such a catastrophic event might have been responsible for the extinction of the dinosaurs.

New Study Suggests Dinosaur Extinction Due to the Extra-terrestrial Impact Event

Chicxulub impact event.

A reconstruction of the Chicxulub impact which marked the extinction of many terrestrial and marine forms of life, including the non-avian dinosaurs.

The “Smoking Gun” Evidence

Such an impact would have left an enormous crater, the search was on to find the “smoking gun” to support the theory regarding a meteorite, asteroid or perhaps a comet hitting the Earth.  Most researchers now agree, that the Yucatan peninsula in the Gulf of Mexico was ground zero.  However, there is a problem, as scientists are aware of a number of other potential candidates responsible for the extinction of a large amount of the planet’s biota some sixty-six million years ago.  For example, the Late Cretaceous was characterised by extensive volcanism.  Huge amounts of lava from the Deccan traps led to the formation of thousands of miles of  flood basalt.  The out-pouring of noxious gases as a result of this extensive volcanism could well have played a significant role in the extinction of many different kinds of organisms too.

Asteroid impact theory challenged: Blame the Deccan Traps.

In a new paper, a team of international researchers led by Dr Celli Hull from Yale University, conclude that the volcanism did not play a huge role in the extinction, but it may have played a significant role in shaping the rise of different species after the extinction event had occurred.

Impact Event the Most Likely Cause of End-Cretaceous Mass Extinction

The extinction of the dinosaurs.

An international team of scientists conclude that it was the extra-terrestrial bolide impact that caused the mass-extinction event.

Picture Credit: Everything Dinosaur

Analysis of Ancient Ocean Sediments

In order to disentangle the relative effects of the volcanism and the impact event, the scientists analysed deep sea sediment sections drilled from the North Atlantic, Pacific and South Atlantic Oceans.  They found that volcanic activity in the Late Cretaceous period caused only a gradual global warming of about two degrees Celsius, but this had no significant effect on marine ecosystems, and cooler conditions had returned prior to the extinction.

Hull et al investigated the timing of the Deccan outgassing by modelling in several scenarios, the effects of the gases ejected by volcanoes (sulphur and carbon dioxide).  Their results suggest that more than half of the total Deccan outgassing occurred well before the impact event, not just before it.  The scientists concluded that the timing of most of the atmospheric pollution from the extensive volcanism, just did not fit the extinction event.  The major volcanism is likely to have occurred at least 200,000 years before the extinction event.

One of the co-authors of the study, Professor Paul Bown (University College London), explained.

“Most scientists acknowledge that the last, and best-known, mass extinction event occurred after a large asteroid slammed into Earth 66 million years ago, but some researchers suggested volcanic activity might have played a big role too and we’ve shown that is not the case.”

The team’s models showed that the changes in the carbon cycle that resulted from the volcanism was mitigated by the oceans absorbing vast quantities of CO2.  This would have limited any global warming.

Fellow co-author Professor Paul Wilson (Southampton University), added:

“There’s been a big row about the cause of the mass extinction for decades.  The demise of the dinosaurs was the iconic event but they were large animals and there weren’t really that many of them so it’s tough to use them to figure out the cause.  We studied microscopic marine organisms called foraminifera and there are thousands of them in a teaspoon-full of ocean sediment.  To get them we drilled into the sea bed in waters nearly 5 kilometres deep not far from the watery grave of RMS Titanic off the coast of Newfoundland using a sort of geology time machine – a drill ship called the JOIDES Resolution run by one the world’s most successful international scientific collaborations, the International Ocean Discovery Program.”

The authors postulate that the volcanism may have played a role in shaping the evolution of Palaeogene species in the aftermath of the end-Cretaceous extinction event.

What About Hell Creek – Were Dinosaurs Already in Decline?

From a scientific perspective, it makes much more sense to examine the fossil record of planktonic foraminifera.  Relying on the non-avian dinosaurs as an indicator of palaeo-climate change some sixty-six million years ago is fraught with difficulties.  For instance, although many different types of life were affected by the end-Cretaceous extinction event, it is often only the dinosaurs that are mentioned by the media.  It is worth remembering that many other lifeforms died out.  There are not that many windows into the end of the Maastrichtian and the earliest part of the Palaeocene (Danian faunal stage).  One such example is the Hell Creek Formation, which provides a record of the last few million years of the Mesozoic.

Hell Creek – Prospecting for Fossils in the Upper Cretaceous Sediments

Looking for fossils - Hell Creek Formation.

Prospecting for fossils – Hell Creek Formation (Montana).

Picture Credit: University of California Museum of Palaeontology

Studies of the number and variety of dinosaur fossils excavated from the Hell Creek Formation and other slightly older geological formations, suggest that in the last ten million years of the Cretaceous, the number of dinosaur species fell by more than fifty percent.

An analysis of the youngest fifteen metres of sediments from the Hell Creek Formation, revealed just eleven different types of dinosaur.  In the uppermost strata, the last three metres of the Hell Creek Formation representing the end of the Cretaceous, only three types of dinosaur were recorded.  Whilst it can be difficult to accurately date and assess the chronology of strata, the study of dinosaur fossils from Hell Creek suggests that the Dinosauria may have been in decline (at least in this part of Laramida), prior to the impact event.  This decline, if it was a decline, could have been caused by the environmental effects of the extensive volcanism, or other factors for that matter.

We suspect that just like the Deccan Traps, this debate is going to rumble on for a considerable period of time.

15 01, 2020

Ediacaran Fossil Site Gains Protection

By | January 15th, 2020|Dinosaur and Prehistoric Animal News Stories, Geology, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

South Australian Fossil Site Purchase Supported by Billionaire

With so much bad news about the environment coming out of Australia due to the devastating bush fires, it is pleasing to report on a conservation success story.   A $1 billion (USD), nature fund has been used to buy a vast tract of outback South Australia containing some of the oldest animal fossils on Earth.  The acquisition safeguards an extremely important fossil site and helps support the Australian Government’s plans to gain World Heritage Site status for the area.

The Nilpena Fossil Fields (South Australia)

The Nilpena fossil fields (South Australia).

The Nilpena fossil fields preserve examples of Precambrian biota.

Picture Credit: Jason Irving

The 60,000-hectare (150,000 acre) Nilpena West property is 370 miles (600 kilometres), north of the South Australian capital Adelaide and was previously part of Nilpena Pastoral Station.  The property includes the Ediacara Fossil Site (Nilpena), which is listed on Australia’s National Heritage List and records a remarkable marine biota, documenting some of the earliest, large, multicellular creatures to have evolved on Earth.

Global not-for-profit organisation The Nature Conservancy, sourced funding from an anonymous donor in October 2019 to allow the purchase and protection to go ahead after the South Australian Government announced in March that it had reached an agreement with the land’s owners to purchase the site.  The purchased land is adjacent to the Ediacara Conservation Park and increases the size of the protected area ten-fold.

The Importance of the Flinders Range

Strange fossils, preserved in the sandstone of the Ediacaran hills of South Australia provided the first substantial evidence for the existence of complex life in the late Precambrian.  In 1946, Australian geologist Reginald Spriggs discovered fossilised impressions in this part of the Flinders Range, his unexpected discovery failed to enthuse the scientific community at first, his paper outlining the discovery was rejected by the academic journal “Nature”.  However, the significance of these exquisitely preserved fossils and what they represented – organisms associated with an ancient marine community, was soon realised.

An Example of Dickinsonia – One of the Fossilised Ediacaran Organisms Associated with the Nilpena Fossil Fields

Dickinsonia costata fossil.

The Ediacaran fossil Dickinsonia costata, specimen P40135 from the collections of the South Australia Museum.  The disc-like Dickinsonia is one of the creatures preserved at the Nilpena fossil site.

Picture Credit: Dr Alex Liu (Cambridge University)

To read an article about the bizarre Dickinsonia: Dickinsonia Definitely an Animal.

The sale has now been finalised with The Nature Conservancy announcing this week that funding from the Wyss Campaign for Nature, the once anonymous donor, had helped secure the acquisition.  The Wyss Campaign for Nature was founded two years ago, by the wealthy, Swiss-born philanthropist Hansjörg Wyss.  The purchased land will be permanently protected and managed by the South Australian Government.  It will be formally allocated to the Ediacara Conservation Park later this year.

A Map Showing the Location of the Nilpena Fossil Fields Relative to the Ediacara Conservation Park

A map of the Nilpena fossil fields site.

Nilpena fossil fields site.  The Nilpena Station purchase will greatly increase the protected area for the fossils.

Picture Credit: The Government of South Australia

The South Australian property is now permanently protected and managed for conservation by the South Australian Government. It will be added to the Ediacara Conservation Park later this year.

Scores of Species

Palaeontologists have excavated many hundreds of specimens representing three dozen different species, most of which are more than 550 million years old.  The fossils provide the first evidence of locomotion and sexual reproduction.  The space agency NASA, has examined the Ediacaran biota in a project to assess how life could evolve on other worlds.

The Nature Conservancy’s Australian Director of Conservation Dr James Fitzsimons explained that this purchase which would permit the formal protection of the 60,000 hectare property was a big win for conservation in South Australia.

He commented:

“The property contains significant biodiversity values including two threatened ecological communities and a number of threatened species.  Most critically, the property also covers extremely important sites that contain the oldest fossilised animals on Earth.”

South Australian Environment and Water Minister David Speirs said Nilpena West would soon be added to the South Australian public protected area estate and managed by the Department for Environment and Water.

The minister added:

“Its inclusion in the conservation estate will link the Ediacara Conservation Park to the Lake Torrens National Park and will support our nomination for the listing of areas of the Flinders Ranges as a World Heritage Site.”

When did life on land evolve?  An Ediacaran related article: When Did Life on Land First Evolve – Does the Ediacaran Biota Provide the Answer?

A recent article about how computerised tomography and other sophisticated research techniques are providing new insights into how the first animals evolved: Chinese Fossils Suggest Animal-like-embryos Evolved Before Animals.

Everything Dinosaur acknowledges the assistance of a press release from The Lead South Australia in the compilation of this article.

14 01, 2020

The First Stegosaur Dacentrurus armatus

By | January 14th, 2020|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

The First Stegosaur Dacentrurus armatus

Situated amongst specimens of marine reptiles in the Mary Anning gallery at the London Natural History Museum is a remarkable fossil specimen.  Behind its glass case the viewer can make out a block of bones containing various vertebrae, a massive right femur (thigh bone), ribs and a near complete pelvis.  At approximately two metres across this is an impressive fossil specimen.  It is the holotype material for Dacentrurus armatus (NHMUK OR46013), the first large collection of dinosaur bones associated with a member of the Stegosauridae to be scientifically described and studied.

The Main Bone Block (D. armatus) at the Natural History Museum (London)

Dacentrurus armatus specimen on display at the Natural History Museum (London).

The Dacentrurus armatus specimen on display at the Natural History Museum (London).

Picture Credit: Everything Dinosaur

The fossils come from a clay quarry close to the town of Swindon in the county of Wiltshire.  Richard Owen (later Sir Richard Owen), who was to play a pivotal role in the foundation of the institute that we now know as the London Natural History Museum, studied the fossils and erected the name Omosaurus armatus in 1875.  The genus name, Omosaurus had already been used to describe a North American phytosaur (O. perplexus) in 1856.  Therefore, the original genus name for this armoured dinosaur was invalidated.  In 1902 the eminent American zoologist, Frederick Augustus Lucas erected Dacentrurus.

With the recently published paper describing a new specimen of Miragaia longicollum, a “Rosetta Stone” moment in vertebrate palaeontology permitting scientists to better understand the Dacentrurinae subfamily of the Stegosauridae, it is fitting that whilst in London an Everything Dinosaur team member took the opportunity to take a photograph of the main Dacentrurus block.  The beautiful fossils are notoriously difficult to photograph, but still, they continue to play a role in helping to decipher Late Jurassic stegosaurs.

One mystery still remains, why is this important dinosaur fossil on display in the marine reptiles gallery?  Perhaps, one day, these hugely significant fossils we will placed in the dinosaur gallery, where visitors could be given the opportunity to learn more about the world’s first extensively studied armoured dinosaur specimen.

To read our recent article on the M. longicollum paper: Turning a Stegosaur Fossil into the Rosetta Stone.

11 01, 2020

Thin-skinned, Grey Duck-billed Dinosaurs

By | January 11th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Thin-skinned, Grey Duck-billed Dinosaurs

Scientists writing in the journal of The Palaeontological Association have published a remarkable study on the properties of the skin of duck-billed dinosaurs.  Analysis of fossilised hadrosaur skin, from the Yale Peabody Museum of Natural History (New Haven, Connecticut), suggests that the skin structure of these dinosaurs had more in common with living birds than with reptiles.  In addition, the skin is much thinner when compared to large, terrestrial mammals of comparable size such as elephants and rhinos.  In a blow to palaeoartists who like to adorn their ornithischian illustrations with a multitude of colours, the scientists conclude from an analysis of potential preserved skin pigments that hadrosaurids were grey in colour.

Hadrosaurs Could Have Been Largely Grey in Colour Just Like Big Terrestrial Mammals Alive Today Such as Elephants

Gryposaurus - Hadrosaur Model available from Everything Dinosaur.

The Wild Safari Prehistoric World Gryposaurus dinosaur model.  The model’s colouration being largely grey may actually reflect the true colouration of duck-billed dinosaurs.

Picture Credit: Everything Dinosaur

Getting Under the Skin of a Dinosaur

Scientists from Yale University, in collaboration with colleagues in Italy, investigated the chemical properties of a section of fossilised duck-billed dinosaur skin that had been preserved in three dimensions. The specimen (YPMPU 016969) was also subjected to detailed chemical mapping and microspectroscopy as well as scanning electron micrographs to establish the anatomical structure.

Two of the three layers associated with skin in tetrapods were identified, the outer layer (epidermis) and the dermis. The innermost layer, the subcutis, could not be identified in this study.  The dinosaur’s scales on the skin surface are very well-preserved.  They form an irregular, pebbly pattern with individual scales ranging in size from under one millimetre in diameter to much larger scales around 12 millimetres across.

Specimen Number YPMPU 016969 – The Fossilised Skin Studied

Fossilised duck-billed dinosaur skin.

The skin preserved in YPMPU 016969 (A), three‐dimensional skin and (B), the fossil counterpart. Scale bar represents 2 cm.

Picture Credit: Yale University

Three-dimensionally Preserved Pigment Bearing Bodies and  Blood Vessels

The detailed analysis of the fossilised skin and the samples taken permitted the scientists to identify three-dimensionally preserved eumelanin‐bearing bodies.  This enabled the researchers to propose that the dinosaur was mostly dark grey in colour, a skin colouration that reflects ecological parallels seen in today’s large, terrestrial animals such as elephants and rhinos.  However, caution is urged when it comes to determining the colouration of these types of dinosaurs.  There might be a preservation bias in favour of pigment cells that produce darker skin tones, other pigments may not have been preserved.  The section of fossil skin also permitted the researchers to trace blood vessels and dermal cells.

The Study Suggests That Large-bodied Hadrosaurids Were Similar in Colour to Today’s Large-bodied Terrestrial Mammals

Analysis suggests grey-coloured hadrosaurids.

A life reconstruction of a grey-coloured duck-billed dinosaur.

Picture Credit: Yale University

Surprisingly Thin Skin

The skin was found to be much thinner than that of living mammals of similar size.  The outer layer of skin is around 0.2 mm in thickness, whilst the dermis is estimated to have been up to 3 mm thick.  Although, no measurements for the subcutis layer could be made, in living elephants the skin is around 10-15 mm thick and in extant rhinos a skin thickness (all three layers, epidermis, dermis and subcutis), of 25 mm is not uncommon.

The relative thickness of the epidermis and dermis in YPMPU 016969 resembles that in birds more closely than that of reptiles.

If the skin of these large, Cretaceous herbivores is so much thinner than previously thought, then how does it fossilise more readily than the integumentary coverings of other dinosaurs?  After all, the most commonly preserved soft tissues associated with ornithischian dinosaurs are skin remains.  The researchers postulate that the unusual layering and the microstructure of hadrosaur skin may play an important role in its fossilisation potential.

The scientific paper: “Three-dimensional soft tissue preservation revealed in the skin of a non-avian dinosaur” by Matteo Fabbri, Jasmina Wiemann, Fabio Manucci and Derek E. G. Briggs published in Palaeontology – the journal of The Palaeontological Association

9 01, 2020

Animal-like Embryos Evolved Before Animals

By | January 9th, 2020|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Animal-like Embryos Evolved Before the First Animals Appear in the Fossil Record

Catching up with our reading, examining university press releases and having a little time to review some scientific literature enabled team members at Everything Dinosaur to get to grips with this research.  A new paper has been published in the journal “Current Biology” that sheds light on how the Animalia evolved.  Researchers led by scientists from the University of Bristol and Nanjing Institute of Geology and Palaeontology (Nanjing, China), have discovered that animal-like embryos evolved long before the first animals appear in the fossil record.

The study centred around a multicellular organism found in 609-million-year-old-rocks in Guizhou Province.  The organism is called Caveasphaera and it blurs the definition as to what is and what is not an animal.  However, analysis of tiny embryonic fossils suggests that as Caveasphaera developed it went from a single-cell stage to a multi-cellular stage and that it developed distinct, specialist cells and tissues.

Remarkable Fossils Reveal Ancient Organism May Have Set the Blueprint for Animal Body Plans

The embryology of 609 million-year old Caveasphaera.

Embryology of 609 million-year old Caveasphaera.

Picture Credit: Philip Donoghue and Zongjun Yin

Animals evolved from single-celled ancestors, subsequently, the Animalia diversified into thirty or forty body plans.  How and when animal ancestors made this evolutionary transition from a microbial state into complex multicellular creatures has been discussed and debated for many years.  The researchers, using sophisticated X-ray computer tomography, analysed tiny fossils from southern China and identified that a key step in this major step in the story of life on our planet occurred long before complex animals appear in the fossil record, in the fossilised embryos that resemble multicellular stages in the life cycle of single-celled relatives of animals.

X-ray Microscopy – Fossils on the Cellular Level

Analysis of the Ediacaran fossils preserved in the strata, revealed that the tiny 0.5 mm in diameter Caveasphaera material had been preserved all the way down to their component cells.

Co-author of the study paper, Kelly Vargas (Bristol University), commented:

“X-Ray tomographic microscopy works like a medical CT scanner, but allows us to see features that are less than a thousandth of a millimetre in size.  We were able to sort the fossils into growth stages, reconstructing the embryology of Caveasphaera.”

Fellow co-author Zongjun Yin, (Nanjing Institute of Geology and Palaeontology), added:

“Our results show that Caveasphaera sorted its cells during embryo development, in just the same way as living animals, including humans, but we have no evidence that these embryos developed into more complex organisms.”

Scanning Electron Microscope Image of Caveasphaera Showing Cell Division

Scanning electron microscope image of Caveasphaera.

A Caveasphaera embryo showing cellular structure and the growing tips where cells are dividing to increase their numbers.

Picture Credit: Philip Donoghue and Zongjun Yin

A Life Cycle that Mirrors the Development of Animals

The researchers concluded that Caveasphaera had a life cycle very close to the life cycle of animals which alternate between single-celled and multicellular stages, however, Caveasphaera goes one step further, reorganising those cells during embryology.  This is the earliest fossil evidence found to date that shows such development and the setting up of more complex distinct tissue layers and organs.

Whether the enigmatic, Caveasphaera is a member of the Animalia remains open to debate.  It resembles the embryos of some starfish and corals but no adult forms are known as they may not have been easily fossilised.

Professor Philip Donoghue from the University of Bristol’s School of Earth Sciences, stated:

“Caveasphaera shows features that look both like microbial relatives of animals and early embryo stages of primitive animals.  We’re still searching for more fossils that may help us to decide. Either way,  fossils of Caveasphaera tell us that animal-like embryonic development evolved long before the oldest definitive animals appear in the fossil record.”

Sequential Development of Caveasphaera Mirrors the Development Seen in the Animalia

Computer generated images show embryology of Caveasphaera.

Embryology of 609 million-year old Caveasphaera.  Computer models based on X-ray tomographic microscopy of the fossils, showing the successive stages of development.

Picture Credit: Philip Donoghue and Zongjun Yin

The scientific paper: “The early Ediacaran Caveasphaera foreshadows the evolutionary origin of animal-like embryology” by Z. Yin, K. Vargas, J. Cunningham, S. Bengtson, M. Zhu, F. Marone and P. Donoghue published in Current Biology.

Everything Dinosaur acknowledges the assistance of a press release from Bristol University in the compilation of this article.

7 01, 2020

Turning a Stegosaur Fossil into the “Rosetta Stone”

By | January 7th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Newly Described Specimen of Miragaia longicollum helps to Decipher the Dacentrurinae

A fossil of a stegosaur discovered in 1959 on the coast of western Portugal has helped to decipher the taxonomic relationships of an obscure sub-family of armoured dinosaurs known from the Late Jurassic.  The specimen number MG 4863 has been identified as an example of Miragaia longicollum, a stegosaur named and described in 2009 from fossils found some 6 miles (10 kilometres) further inland.

MG 4863 has been described as a “Rosetta Stone” specimen, just as the discovery of the Rosetta Stone was vital in helping scholars to interpret and understand ancient Egyptian hieroglyphics, these fossils, that had languished in storage for sixty years, can help palaeontologists to distinguish between different genera of closely related stegosaurs.

Laid Out in an Approximate Skeletal Reconstruction (MG 4863) – Newly Described Miragaia longicollum Specimen

Views of the Miragaia longicollum specimen ( MG 4863)

Miragaia longicollum specimen (A) before preparation and (B) after preparation. Material is laid out in approximate articulation.

Picture Credit: Costa and Mateus published in PLOS One

The picture (above), shows the fossil material associated with MG 4863 prior to preparation (September 2015) and after preparation (May 2017).  The fossils have been positioned in an approximate skeletal layout, the box in (B) contains unidentified fossil fragments.

Although far from complete and lacking any evidence of a skull, these fossils, that had been stored in an unprepared state at the Alfragide campus of LNEG (Laboratório Nacional de Energia e Geologia, Portugal), consist of bones that were not part of the original holotype specimen for M. longicollum (specimen number ML 433).  Thus, palaeontologists have more parts of the skeleton of Miragaia longicollum to study and this newly described specimen has helped to decipher the differences between Miragaia and the closely related Dacentrurus.

The Dacentrurinae Deciphered

The first armoured dinosaur to be scientifically described was Dacentrurus armatus (although it was originally named Omosaurus armatus by the famous English palaeontologist Richard Owen).  It was named from a jumbled up set of bones preserved in a block discovered in a clay quarry in Wiltshire (southern England).  The fossilised bones mostly represent the back-end (posterior) portions of an armoured dinosaur.  For a considerable period, stegosaur fossils from strata approximately the same age from the Iberian peninsula were referred to as Dacentrurus.  When ML 433 was excavated all that changed and this part of Europe had its very own stegosaur Miragaia longicollum.  However, the holotype (ML 433), represented the front end (anterior) of the animal, so direct comparisons between Dacentrurus and Miragaia were not possible.

Now that palaeontologists have more fossils of Miragaia to study, thanks to the Alfragide campus specimen, clear differences between these two taxa can be identified, which reinforces their validity.  In addition, ML 4863 is the the most complete dinosaur described from Portugal and the most complete stegosaur described from the whole of Europe.

Comparing the Holotypes of Dacentrurus armatus and Miragaia longicollum with the Newly Described Miragaia Material (ML 4863)

Dacentrurus and Miragaia compared.

Comparing Dacentrurus with Miragaia.  Known fossil bones are shown in white.

Picture Credit: Costa, Mateus et al published in PLOS One with additional annotation by Everything Dinosaur

Both the Miragaia holotype (ML 433) and this newly described specimen (MG 4863), are associated with the Upper Jurassic Lourinhã Formation.  Writing in the on-line academic journal PLOS One, the researchers (Francisco Costa and Octávio Mateus), provide a revised diagnosis for both M. longicollum and D. armatus.

A Land Bridge Between Iberia and North America – Late Jurassic Faunal Interchange

Significantly, the scientists conclude that Miragaia was closely related to a Late Jurassic stegosaur named Alcovasaurus longispinus, which is known from hip bones and other fragmentary fossils associated with a Morrison Formation outcrop in Natrona County (Wyoming, USA).  Not only does MG 4863 help to describe and define two European stegosaurs but it lends weight to the idea that there was an ephemeral land bridge between North America and Iberia that allowed faunal exchange.

A Scale Drawing of Miragaia longicollum

Scale Drawing of Miragaia

“Long-neck from Miragaia”.  A scale drawing of M. longicollum.

Picture Credit: Everything Dinosaur

We have two species of the carnivorous Late Jurassic dinosaur Torvosaurus identified, one from the western United States (T. tanneri) and one from Portugal (T. gurneyi) and now the idea of there being links between the Iberian landmass and North America is reinforced by the conclusion that Miragaia from Portugal and Alcovasaurus from Wyoming were closely related.  Indeed, Alcovasaurus is so similar to Miragaia that the researchers propose that it should be assigned to the same genus and renamed Miragaia longispinus.

To read Everything Dinosaur’s article from 2009 about the discovery of Miragaia longicollumA New Long-necked Stegosaur from Portugal.

4 01, 2020

A New “Thunder Lizard” Tralkasaurus

By | January 4th, 2020|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

A New Abelisaurid (Tralkasaurus cuyi) from Argentina

A team of scientists based in Argentina have described a new species of abelisaurid from the Huincul Formation in northern Patagonia.  The new dinosaur is represented by a fragmentary skeleton consisting of caudal vertebrae (tail bones), a bone from the upper jaw (maxilla), a distorted pelvic girdle and sacral vertebrae.  Although the fossils were found in a disarticulated state and quite widely scattered, it is likely that the bones represent a single, individual animal.  With an estimated body length of around five metres and a hip height of approximately 1.5 metres, this newest member of the Abelisauridae, named Tralkasaurus cuyi, is much smaller than abelisaurs such as Carnotaurus sastrei, Abelisaurus comahuensis and Ekrixinatosaurus novasi. 

Writing in the “Journal of South American Earth Sciences”, the researchers, which included Mauricio Cerroni, a PhD student at the Museo Argentino de Ciencias Naturales, Buenos Aires (Argentina), conclude that Tralkasaurus probably occupied a different ecological niche compared to the much larger and heavier Late Cretaceous abelisaurids.

A Size Comparison Between Carnotaurus sastrei and Tralkasaurus cuyi

Tralkasaurus cuyi and Carnotaurus sastrei size comparison.

A size comparison between Tralkasaurus cuyi and Carnotaurus sastrei.  Tralkasaurus very probably had a typical abelisaurid body plan, but its size suggests that it was a secondary predator, specialising in hunting other types of prey compared to the much larger carnivorous dinosaurs that it co-existed with.

Picture Credit: Everything Dinosaur

A New “Thunder Lizard”

This new dinosaur was found at the Violante Farm site, in Río Negro province (northern Patagonia).  The sandstones of the Huincul Formation has yielded a diverse range of theropods including the giant carcharodontosaurid Mapusaurus (M. roseae), which is estimated to have measured around 12 metres in length along with the at least 6-metre-long Gualicho (G. shinyae), tentatively described as a member of the Neovenatoridae family and two other abelisaurids Skorpiovenator (S. bustingorryi) and Ilokelesia (I. aguadagrandensis).

The genus name translates as “thunder lizard”, in the native Mapuche language.

Life Reconstruction with Scale Tralkasaurus cuyi

Tralkasaurus scale drawing.

Tralkasaurus cuyi scale drawing.

Picture Credit: Everything Dinosaur

Being much smaller than other abelisaurids such as Abelisaurus and Carnotaurus suggests that this new taxon probably occupied a different ecological niche within the ecosystem.

The scientific paper: “A new abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro province, Argentina” by M. A. Cerroni, M. J. Motta, F. L. Agnolína, A. M. Aranciaga Rolando, F. Brissón Egli and F. E. Novas published in the Journal of South American Earth Sciences.

29 12, 2019

Carboniferous Parental Care

By | December 29th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Carboniferous Fossil Provides Evidence of Parental Care

Parental care is a common behaviour amongst mammals, the chances of the offspring surviving are enhanced by the parents making an investment in looking after their young, but when did this behavioural strategy evolve in the ancestors of the Mammalia?  This is a tricky question to answer as evidence for such behaviours is rarely preserved in the fossil record, but a remarkable discovery inside a lithified tree stump dating from around 305 million years ago from Cape Breton Island, Nova Scotia (Canada), may have provided palaeontologists with a fresh insight into prehistoric parenting.

A team of scientists writing in the academic journal “Nature Ecology & Evolution” report the discovery of fossilised remains of an adult lizard-like creature in association with a very young member of the same species preserved within the tree stump.  Finding an adult and associated conspecific juvenile has been interpreted as evidence of the parent staying close to its offspring and therefore a demonstration of parental care.

The creatures are members of the Varanopidae family, so called as these creatures resemble extant monitor lizards (Varanus), but they are not closely related to monitor lizards and are a new genus.  They have been named Dendromaia unamakiensis and if this is prehistoric parental care, then it predates the previous earliest evidence by some forty million years.

Evidence of Parental Care in a Synapsid (Dendromaia unamakiensis)

Dendromaia unamakiensis life reconstruction - evidence of parental care in a synapsid.

Dendromaia unamakiensis life reconstruction.

Picture Credit: Henry Sharpe

A Varanopid (Synapsid) Caring for its Young

The Varanopidae are geographically widespread and temporally diverse.  Most of these animals were around 1 metre in length, much of their body length was made up of their long tails.   They evolved during the Carboniferous and persisted into the Middle Permian.  Varanopids are regarded as one of the most successful of the early types of amniotes, however, whether they are ancestral to modern mammals and members of the Synapsida or whether they are actually diapsids is an area of debate amongst palaeontologists.

Commenting on the significance of the fossil discovery, lead author of the scientific paper Professor Hillary Maddin (Carleton University, Ottawa, Canada), commented:

“Parental care is a behavioural strategy where parents make an investment or divert resources from themselves to increase the health and chances of survival for their offspring.  While there are a variety of parental care strategies, prolonged postnatal care is amongst the most costly to a parent.  This form of parental care is particularly common in mammals, as all mammalian offspring demand nourishment from their mothers.”

The Slab and Counter Slab with the Preserved Remains of the D. unamakiensis Fossils

Dendromaia unamakiensis slab and counter slab.

The slab and the counter slab with the preserved Dendromaia unamakiensis fossils.

Picture Credit: Maddin et al

The researchers concluded that this was evidence of parental care as the preservation of delicate details and structures in the fossils indicate a rapid burial with little movement after death.  The adult and the juvenile were close to each other at the time that they died.  The location of the young animal beneath the hindlimb and encircled tail of the adult resembles a position associated with animals living in a den.

Earliest Evidence of Prolonged Parental Care

The fossils could represent the earliest known record of prolonged parental care.  Prior to this discovery, the previous earliest record of this sort of parental behaviour was identified in a varanopid from the Middle Permian of South Africa.  A scientific paper was published in 2007, describing the discovery of five articulated conspecific varanopid specimens, one of which was much larger than the others.  This was interpreted as an adult and four juveniles, a family group with the older animal looking after its offspring.

Whether Dendromaia is a synapsid of diapsid might be debatable, but whatever the taxonomic relationship to other more advanced amniotes, this fossil discovery suggests that parental care is deeply rooted within the Amniota clade and that parenting behaviour might have been more widespread amongst Palaeozoic tetrapods than previously thought.

The scientific paper: “Varanopid from the Carboniferous of Nova Scotia reveals evidence of parental care in amniotes” by Hillary C. Maddin, Arjan Mann and Brian Hebert published in the journal Nature Ecology & Evolution.

28 12, 2019

Everything Dinosaur’s Top Ten Blog Posts of 2019 (Part 2)

By | December 28th, 2019|Adobe CS5, Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Everything Dinosaur’s Top Ten Blog Posts of 2019 (Part 2)

Today, we conclude our review of the top ten blog posts written by Everything Dinosaur team members in 2019.  We have produced a blog post for every day of the year and as a result we have covered a tremendous range of topics from new fossil discoveries, highlighting research, the introduction (and retirement) of prehistoric animal replicas, book reviews, artwork created by academic illustrators and scientific discoveries.

Here is our countdown of the top five.

5). Ngwevu intloko – New Dinosaur “Hiding in Plain Sight”

Over the summer, Everything Dinosaur published a wide range of articles.  A new bizarre, shovel-mouthed duck-billed dinosaur (Aquilarhinus), was reported and news of a fast-running Triassic theropod from Switzerland (Notatesseraptor) broke.  We had strange prehistoric parrots, an analysis of the cranial capacity of “parrot lizard” Psittacosaurus and herbivorous crocodylomorphs.  However, number five on our list concerns the discovery of a new type of Triassic herbivorous dinosaur that was found in a museum cabinet.

Fossils once thought to represent an unusual specimen of Massosopondylus (M. carinatus) in the collection of the University of Witwatersrand (South Africa), were assigned to their own genus. Student Kimberley Chapelle and colleagues identified a total of twenty-two characteristics that supported the establishment of a brand new dinosaur genus.  The new dinosaur was named Ngwevu intloko, this member of the Sauropodomorpha had been hiding in plain sight within the vertebrate fossil collection of the University for more than three decades.

Views of the Skull of Ngwevu intloko

Views of the skull of N. intloko.

Views of the skull of Ngwevu intloko.

Picture Credit: Kimberley Chapelle/University of Witwatersrand

4). Keresdrakon vilsoni – Toothless Pterosaur from an Ancient Desert Ecosystem

September and thirty days of blog posts covering stiff T. rex skulls and subsequently how the skull of T. rex may have helped it to keep cool, dinosaur model deliveries to hotels, the most complete dinosaur fossil from Japan (Kamuysaurus japonicus) and the Asian origins of Saurornitholestes, but our number four features a newly described species of pterosaur from Brazil.

Researchers, writing in the academic journal “Anais da Academia Brasileira de Ciências”, identified a new species of edentulous flying reptile that co-existed with the pterosaur Caiuajara and may have fed on its young.  Described as part of a non-tapejarid lineage of pterosaurs outside the Tapejaromorpha, Keresdrakon provides a new perspective on the paleoecology of a Cretaceous desert environment.

Keresdrakon Life Reconstruction It Feeds on the Carcase of a Contemporary Dinosaur (Vespersaurus) whilst a Second Keresdrakon is Mobbed by Juvenile Caiuajara

Keresdrakon life reconstruction.

Keresdrakon life reconstruction, feeding on the carcase of a Vespersaurus.

Picture Credit: Maurilio Oliveira

An honourable mention to Cryodrakon boreas the first pterosaur to be described which is unique to Canada.

3). A Potential Terrestrial Tetrapod that May Not Have Gone onto Land

In October, Everything Dinosaur team members covered the amazing TetZooCon event in London, the naming of a new, basal carcharodontosaurian theropod from Thailand (Siamraptor suwati) and the reclassification of crocodiles in New Guinea.  A team of researchers, writing in “Nature” put forward an intriguing new hypothesis that some of the first vertebrates that were capable of terrestrial locomotion may have never left the water.  Parmastega aelidae was a sharp-eyed predator that may have ambushed invertebrates that ventured too close to the sea.

With eyes positioned towards the top of their heads, Parmastega was capable of observing life on land and potential prey without leaving the water.

Life in a Late Devonian Coastal Lagoon (Sosnogorsk, Russia)

Parmastega aelidae life reconstruction.

Sosnogorsk lagoon with Parmastega aelidae hunting behaviour.

Picture Credit: Mikhail Shekhanov for the Ukhta Local Museum

2).  Unusual Styracosaurus Skull Might Change the Way New Dinosaurs are Identified

The first fossil evidence of feathered polar dinosaurs, plans to map extra-terrestrial space objects in a bid to prevent Earth impact events, limited edition dinosaur models, a new predatory dinosaur from Brazil – Gnathovorax cabreirai, all featured in October.  A fossil ape from the Miocene of Germany, Poland’s first pliosaur, Rebor Komodo dragons, a new megaraptorid from “Down Under” and the discovery of a Styracosaurus skull that might just turn palaeontology on its head were also discussed.  “Hannah” an asymmetrical Styracosaurus skull named after the pet dog of palaeontologist Scott Persons has cranial imperfections that could alter the way that scientists identify new species of dinosaur.  Whoops, looks like there may have to be another revision of the Centrosaurinae.

Palaeontologist Scott Persons Poses with the Two “Hannahs” in His Life “Hannah” the pet dog and “Hannah” the Styracosaurus

Scott Persons with dog and "Hannah" the Styracosaurus.

Scott Persons with “Hannah” the Styracosaurus and his dog.

Picture Credit: Scott Persons/University of Alberta

1). Asfaltovenator vialidadi – A New Basal Allosauroid from Argentina

Our blog articles this month have covered such varied topics as galloping crocodilians, 7,000 Facebook “likes”, the announcement of new for 2020 Papo prehistoric animal figures, dinosaur teeth replacement, how to distinguish teenage tyrannosaurs and Mimodactylus libanensis, a new toothy pterosaur from the Late Cretaceous of Lebanon.

However, since we started this top ten countdown with a fossil discovery from North America and despite the focus on asymmetrical dinosaurs, we shall conclude with a dinosaur from the opposite end of the Americas.

Asfaltovenator vialidadi from the Cañadón Asfalto Formation (Chubut Province, Patagonia) roamed South America perhaps as early as 170 million years ago.  Its discovery is important, as most Middle Jurassic theropods are only known from quite fragmentary material and this dinosaur, described as a basal allosauroid, has traits linking it to both the allosauroids and the megalosauroids.  The fossils suggest that the Allosauroidea and the Megalosauroidea evolved from a common ancestor.

A Life Reconstruction of the Newly Described Asfaltovenator vialidadi 

Asfaltovenator illustration.

Asfaltovenator life reconstruction.  The theropod dinosaur shows a mix of anatomical characteristics linking the Allosauroidea and the Megalosauroidea.

Picture Credit: Gabriel Lio/Conicet

Team members at Everything Dinosaur look forward to posting up more blog articles that help to work out taxonomic relationships within the Dinosauria and improve our understanding of ancient life still further in the coming months.

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